Prostaglandins are hormone-like chemical messengers that regulate a host of physiological activities essential to life, such as the contraction and relaxation of smooth muscle tissue, the dilation and constriction of blood vessels, control of blood pressure, and modulation of inflammation. In nature, prostaglandins are derived from arachidonic acid (AA) and transformed by prostaglandin synthetase into a number of structurally related carbocyclic molecules. These sensitive and labile molecules are not stored in the body but are synthesized in response to stimuli. They were first discovered in the early 1930s by von Euler and by the mid 1960s the structures of the first family of prostaglandins was uncovered by Bergström et al.
The breadth of biological activity, coupled with their challenging molecular architecture has made prostaglandins popular targets in synthesis for over 40 years. Furthermore, prostaglandin analogues are widely used as pharmaceuticals and some have become billion dollar drugs, such as latanoprost, an analogue of the prostaglandin PGF2α, which is used in the treatment of glaucoma.

However, the currently available ways of manufacturing prostaglandins still require lengthy syntheses. A synthesis strategy developed by E. J. Corey in 1969, as described in Corey et al., Journal of the American Chemical Society, 1969, 91, 5675, involves formation of a key intermediate, the Corey lactone, synthesised in 9 steps from cyclopentadiene. The other members of the family of prostaglandins can be assembled from this lactone; prostaglandin PGF2α, for example, can be assembled from the Corey lactone in 8 further steps, i.e. in 17 steps from cyclopentadiene.

The manufacture of latanoprost requires 20 steps and utilizes the original 1969 synthesis developed by E. J. Corey, including the use of the Corey lactone.
Both the naturally occurring prostaglandins and their synthetic analogues such as latanoprost contain a number of chiral centres. It is well known that enantiomerically pure drugs are usually more biologically active than their racemic counterparts. In some cases the redundant enantiomer even has undesired side effects. It is highly desirable, therefore, to synthesize prostaglandins in enantiomerically pure form.
Despite the enantioselective tools available to modern synthetic chemists, a more efficient synthesis for manufacturing prostaglandins has remained elusive. Most if not all of the currently available ways of manufacturing prostaglandins require lengthy syntheses where every step costs time and money, generates waste, and is invariably accompanied by material losses. A need remains for new methods of synthesizing prostaglandins which are more efficient and less expensive than the existing syntheses.
It is an aim of the invention to provide a significantly shorter synthesis for manufacturing prostaglandins, including both the naturally occurring prostaglandins, such as PGF2α, and their synthetic analogues, such as latanoprost.